<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
#left {
	background-color: #9F0;
	float: left;
	width: 120px;
}
#right {
	background-color: #0FC;
	float: right;
	width: 120px;
}
#main {
	background-color: #C6C;
	margin-right: 122px;
	margin-left: 122px;

}
#foot {
	background-color: #FCF;
	margin-right: 120px;
	margin-left: 120px;
}
#container {
	margin: auto;
}
</style>
</head>

<body>
<div id="container">
<div id="left">此处显示  id "left" 的内容</div>
<div id="right">此处显示  id "right" 的内容</div>
<div id="main">此处显示  id "main" 的内容</div>
<div id="foot">footddddddddddddddddd<br />
footddddddddddddddddd<br />
footddddddddddddddddd<br />
 </div>
 </div>
</body>
</html>
